Mounting ULTRIX CDROMs on Linux

[Jonathan Stone]

[[ apologies for top-post: Y! issue ]]

I know that to be bootable on DECstation/VAX/early Alpha, CD-ROMs needs to be jumpered to 512-byte blocks. Like RRD4x.

Does the burning CD write need to be jumpered to 512-bytes? Or can one write on a "normal" CD burner, then read on a 512-byte-block CD-ROM ? If the former, I guess I'll have to find an old, 512-byte-block jumperable SCSI CD burner.
     On Thursday, May 20, 2021, 02:15:39 PM PDT, Christian Groessler via cctalk <cctalk at classiccmp.org> wrote:  
 
 On 5/20/21 11:05 PM, Jonathan Stone via cctalk wrote:
>  MacOS (Mojave) can mount an image read from a 512-byte UFS CD.
>
> What does one have to do (Linux, MacOS, *BSD) to write such an image to the CD with 512-byte blocks, so it can be read by a DEC boot-ROM?


I think that's a property of the CD drive, not the disk itself.

I've got a Plextor CD writer which can be jumpered between 2048 and 512 
byte blocks.

I was able to boot the Ultrix installation CD (MIPS) on a DECServer.

regards,
chris